Heating device



Nov. 13, 1945. A. BURROWS HEATING DEVICE J%@ W J A TTORNE Y Patented Nov. 13, 1945 HEATING DEVICE Lawton Arthur Burrows, Woodbury, N. J., assignor to E. I. du Pont de Nemours & Company, Wilmington, DeL, a corporation of Delaware Application April 16, 1943, Serial No. 483,232 Claims. (of; 158-27) small area be heated. The use-of explosive rivets in the repair of various articles of manufacture is one example. The field repair of such articles in which all or some of the parts thereof are secured together by means of explosive rivets creates a serious problem. In these circumstances it is necessary to have available a heating device characterized by the fact that it may be operated independently of electricity, since this source of heat is usually not accessible in isolated localities; that it may be operated at a controlled temperature irrespective of the surrounding weather conditions; that it may be employed without directly heating the structure to be riveted, because otherwise the requisite temperature control is not attained, with the result that the rivet is not properly expanded, if at all. Since a large number of rivets per unit area are usually employed, a heating tool which will easily and quickly initiate their explosive charges is also necessary.

An object of the present invention is to provide an improved heating device for applying heat to surfaces of small area. Another object is such a heating device including means for accurately and efliciently controlling the temperature thereof irrespective of the surrounding weather conditions. A further object is a heating device which may be used effectively in isolated localities for the repair of articles, the structure of which is held together by means of explosive rivets. A still further object is a device of the type described adapted for using gasoline, alcohol or other vaporizable or finely divided fuel. An additional object is such a device which can be handled readily.

Other objects of the invention relate to various features of construction and arrangement of parts, which will be apparent from a consideration of the following specification and. accompanying drawing.

The single figure of the drawing is a general side elevation of a preferred structure of the present invention. In the drawing, I represents a cylindrical tank or receptacle for holding a supply of fuel, said tank having a handle or grip 2 to facilitate handling of the device, extending rearwardly and downwardly from the rear portion thereof. Asshown, this handle is in the form of a pistol grip and preferably is constructed of nonconducting material such as plastic, Wood, and the like. The top of the tank is provided with a fuel passage 3 with a removable cap or closure 4 threaded thereon.

The pump structure 5, extending into the rear terminus of the fuel tank, has a plunger 6 whereby air can be pumped into the tank I, thereby keeping the contents of said tank under pressure. When the plunger is not in use, the greater portion thereof is retained inside the tank by means of a spring clamp I attached to said tank. Extending forward from the central portion of the fuel tank I is the member 8 having aconduit 9 communicating with the tank and terminating into a burner tip to. This conduit can be closed by the needle valve II which is threaded into said conduit. The end of the stem of saidvalve opposite this conduit is provided with a knurled head l2 for facilitating rotation of said stem. Forwardly, member 8 is reduced in diameter to form the threaded member l3, and in turn the latter is likewise reduced to a still lesser diameter to form member I4 through which conduit 9 extends and terminates. Detachably secured to said heating device at a Dosition substantially midway between the contact tip and the handle is the stand 22 which is employed as a supporting means. If and when desired, this stand may be retracted so as to fit snugly against the heating device. The open priming pan 23, the function of Which will be disclosed hereinafter, is attached'to member 8.

Numeral l5 represents a perforated metal cylinder threaded onto member I3 and to the heater bit I6. This cylinder, with its rows of ports H and rectangular openings 18 parallel to the longitudinal axis thereof providing proper ventilation, serves as a combustion chamber for the fuel. passing thereinto'from the tank I by way of the conduit 9. As shown, the inside diameter of said cylinder gradually decreases fromits rear end to its forward end to which the heater bit is attached thereby forming a conical bore, while its outside diameter remains constant throughout its length. The contact end of the heating device, that is the heater bit or tip I6, is suitably tapered to accomplish the desired result. Of course, these contact members may assume widely-varying shapes in order that they may be employed in those applications in which movement of the heating device is greatly restricted. The heater bit is constructed of metal or alloys having very high heat conductivity and possessing high stability with respect to oxidation and corrosion. While silver and various silver alloys may be used, silver-silicon alloy, as disclosed in the copending application of Burrows and Myers, filed June 18, 1942, Serial No. 447,542, is preferred.

Temperature control of the contact member is attained by suitable manipulation of the sleeve l9, which is slidably secured to the outside forward end of cylinder l5,and which overlies and contacts said portion of the cylinder. This around a portion of the periphery thereof.

inder l5.

by releasing the set screw and'rotating theEsleeve about said cylinder in either direction. When the sleeve is adjusted to the desired position, it

may be held from possibility of displacement during operation by tightening the set screw. As the sleeve is projected longitudinally along the cylinder, it opens or closes any desired number.of the'perforations or ports insaid cylinder. Obviously, whether the. ports are opened or closed depends on which direction the sleeve is rotated about the. cylinder, and the number of ports opened or closed depends on the distance the sleeve is rotated. The sleeve may be regulated to create a dead air space in the underlying portion of cylinder [5. .By dead air space is meant the space in which substantially no combustion occurs. Thus by manipulating the sleeve to .change its projection ,on the cylinder, the length of this dead air space can be regulated. Obviously, the greater the -length of this space the lower the temperature of the heater tip and vice versa. While the temperature of the heater tip may be regulated to a certainextentby means of the needle valve H, such a regulating means alone is unsatisfactory. Furthermore, better performance is attained by'operating with said valve completely open, since this avoids stoppage and prevents the flame from being misdirected orextinguished by wind or air currents'generally. In operation, after the sleeve l9 has beenadjustecl and secured as hereinbefore describedat a position to. give the temperature desired, and after a pressure has beenbuilt up in tank I by means of the plunger 6, the cylinder I5 isbrought to a temperature suitable for combustion under the:circumstances. The desired temperature is attained by suificiently opening valve I l to allow fuel to pass fromfthetank into the prim'inglpan zstymy of conduit ,9, closing said valvefigniting the .fuel insaid pan, allowing combustion'to takeplace thereinuntil'substantially all of said fuelf'has been consumed; -Conduit 9 is then opened completelyfby turning thejn'eedle valve krioblZi 'Ifhis'cau'ses fuel from'the tank to be forced out at theburner tip 'lfl'andinto the combustion chamber l5. The diminishing flame-from theprirning panis sufficient to ignite the fuel as it leaves the "burner tip. Thus the flame sweeps through said chamberand heats the contact member -l 6 to, and maintains it substantially at, the temperature for which'the heating device was adjusted; While gasoline is the preferred fuel for the heating device of-this invention, other vaporizable liquids as well as gases may beused also. I While a preferred form of this .invention has been described 'hereinbef'ore by way of illustration, it will' be appreciated that said invention is not limited thereto but that it is susceptible to various modifications as to types "of materials used and the mannerin which they are attached to each other, andother alterations. "I .do-not intend to be limited therefore except as indicated in-theifollowingclaims.

Iclaim: L In a heating device for the localized application of heat and having at one extremity a contact tip of high heat conductivity, and having at the other extremity a fuel container: means for developing pressure therein, means for controlling the flow of fuel therefrom; a combustion chamber intermediate said contact tip and said container characterized by a plurality of ports therein, and

a sheath about said combustion chamber movable jtherealong' in such manner as to permit closing successively any desired number of said ports starting with the one nearest to the tip and thereby to control the temperature of the contact tip.

2. In a heating device for the localized application 'of heat and including a fuel container: means for developing pressure therein, means for controlling the passage of fuel therefrom, a contact tip adaptedto become heated by the combustion of said fuel, a stand connected to said device at a point substantially midway :between the two extremities thereof, and'a priming pan attached to the bottom of the combustion chamber hereinafter mentioned; a combustion chamber intermediate said contact tip and the fuel exit end of said container characterized by a plurality of ports, and a sleeve fitted snugly about said chamber movable therealong to :permit successive closing of any desired number of said ports starting with the one nearest to .the tip and thereby to control the temperature of the contact tip.

3. In a heating device, .a fuel receptacle .at the rear terminus thereof having a pump structure built therein, a needle valve forwardly disposed on said receptacle, a contact .tip of high heat conductivity at the forward terminus of said heating device, a perforated cylinder. engaging said tip at one end and saidvalve at its other end, temperature control means forwardly -disposed on said cylinder comprising a tubular sleeve, means for projecting the sleeve .longitudinally along the cylinder to successively open or close any desired numberof ports therein and thereby to decrease or increase respectively the dead air space within the combustion-chamber, and means attached to the cylinder for locking said sleeve at its projected positions.

4. In a heating device suitable for explosive rivets, a fuel receptacle at the rear terminus thereof having a handle thereon and a pump structure built therein, a needle valve forwardly disposed on said receptaclaa contact tip ofhigh heat conductivity at-theforward-terminus of said heating device; a perforated cylinder engaging said tip at one end and said valve at its other end, temperature control means comprising a tubular-sleeve .slidably overlying and contacting the forward portion .of said-cylinder, .a slot in said sleeve for longitudinally projecting same along the cylinder -.to successively open or close any desired number of ports-therein :and thereby to decrease or increase respectively the .dead air space within the combustionchamber, and-a' set screwin the cylinder extending through-said-slot in slidable relationship therewithfor locking said sleeve at its projected positions.

5. The heating device of claim 4, in which the thereby to .decrease or increase respectively .the

a dead air space within the combustionchamber.

.LAwrroN RTHUR. BURRows. 

